1. Field of the Invention
The present invention relates to a method of manufacturing semiconductor devices, and more specifically, to a method of forming isolation films of semiconductor devices.
2. Discussion of Related Art
In a method of manufacturing semiconductor devices, an isolation film for separately defining an active region and a non-active region is formed. Recently, as semiconductor device becomes higher integrated and dense, a STI (Shallow Trench Isolation) process has been employed.
As the depth of the isolation film increases due to reduction of a pattern space even through the STI process, however, void, etc. is generated in insulation films buried in trenches.
Further, when the isolation film is formed by means of the STI process, the semiconductor substrate is etched to form the trench. As plasma is used upon etching, there is a problem in that plasma damages are generated in the semiconductor substrate that will be defined as the active region.
Furthermore, as plasma is used in a deposition process of the insulation film, there is also a problem in that plasma damages are generated.
Moreover, in the formation process of the isolation film, sidewall oxide films are formed on trenches sidewalls. In this case, there is a problem in that moat fail is generated in top corners of the isolation film due to the sidewall oxide films.